"It's not nice to fool with Microsoft!!!"
The issue has more to do with the game's programming paradigm. When it was written (Windows XP, and 32-bit), there were only "dreams" of multi-tasking, and "fake" alternatives to it, of which, most of the current technologies really are nothing more than more "efficient" ways to simulate multi-tasking, based mostly on the hardware resources available in the 'modern' computer... but I digress. SH4 is a single-core game, that assumes its address space is the same, no matter what you do in windows. It is for this reason that "swapping out" to the OS "kills" the audio stream, sometimes resulting in an address change of the buffer for the game (from Windows, which leads, guides and directs all aspects of one's computer life), which sometimes results in "odd" behavior when the game once again gains focus. Your current technique apparently minimizes these "issues", but it still might just be a roll of the dice before you get the CO2 not clearing, or the cloud of steam following your boat about the seas of the world, or anyone of a varied sort of maladies yet to be encountered. To keep the audio stream "alive", the game needs to keep "focus", which of course negates the computer's use for anything other than SH4 exclusively.
